Breakdown of No sabes el código del maletín; no lo guardes.
no
no, not
del
from the / of the
saber
to know (facts) / to hear from (someone)
lo
it / him (direct object)
Questions & Answers about No sabes el código del maletín; no lo guardes.
Why is lo placed before guardes? Shouldn't pronouns attach to the command?
Why does guardar change to guardes here? Isn't the tú form guardas?
You use guardas for normal statements like "you put away". But for negative commands with tú, AR verbs like guardar swap their usual A for an E ending. That is why it becomes no guardes.
How do we know what lo means in this sentence?
lo means "it" and replaces a masculine singular noun. Here, we have two options: el código (the code) and el maletín (the briefcase). Common sense tells us it replaces the briefcase, since you would put away a briefcase rather than a code!